Students have homework everyday. Please check student agenda.  If it is not a written assignment, they could read, study all notes, organize notebooks, catch up on other missed assignments etc..Here is a list of websites that may help:

http://www.math.com/students/homeworkhelp.html

http://www.discoveryeducation.com/students/

http://www.infoplease.com/homework/

http://kidshealth.org/kid/feeling/school/homework_help.html

http://www.scholastic.com/parents/resources/collection/homework-project-tips/homework-help